浅谈低压无功功率补偿

本文介绍低压无功功率在供电电网中的作用及影响,并简述无功功率补偿装置的设计原理及重要性。     

IG541混合气体灭火系统在成都地铁中的应用研究

根据地下轨道交通的消防特点,结合成都地铁工程设计实例,对气体灭火系统的控制及操作方式进行深入介绍,并着重论述气体消防系统在地铁设计中的应用:从环保、安全、经济、灭火效率及对被保护对象影响等方面对七氟丙烷与IG541混合气体进行比较,具体分析两种气体环保指标ODP、GWP、ALT值和对人员安全性指标LOAEL、NOAEL、LC50值,得出IG541混合气体适合于地铁地下车站的气体灭火系统的结论。     

Integrated coastal water monitoring

Geographical Information Systems (GIS) are important took for environmental monitoring and management. However, their limitations in dealing with complex, dynamic, and mission‐critical situations call for alternative approaches. Integrating GIS with dynamic simulation models offers one such solution. Numerical models that simulate physical, chemical, and biological processes greatly increase our understanding of the environment. Many of these models use refined forecast information to accurately predict processes that help in monitoring and managing the environment. Integrating these models with GIS offers new functionalities. The present research couples the MIKE21 comprehensive modeling system for two‐dimensional free surface flows with the spatial analysis strengths of the ArcView GIS. The southern coastal water system of Singapore serves as the study area. The aim is to develop a comprehensive software system that provides support for both environmental managers and land‐use planners in making their decisions.     

站间计轴设备在线监测系统

通过监测并记录站间计轴设备的主要运行状态,能够实现对计轴设备实时监测,方便日常维护,预防计轴设备故障的发生,降低设备故障延时。详细论述了站间计轴设备在线监测系统的结构与功能,有很高的推广使用价值。     

ZD(J)9型电动转辙机锁闭机构改进措施

现场使用的ZD(J)9型电动转辙机出现过操纵道岔完成锁闭时锁闭增力动程过大,造成道岔密贴表示不准确的状况。通过分析锁闭机构增力动程,设计出新的转辙机锁闭结构,可有效解决锁闭增力动程过大导致的道岔密贴表示不准确问题。     

21世纪世界新秩序——几种基本理论模式述评

在人类进入21世纪之后，世界需要建立什么样的新秩序才能更好地服务于人类社会?这个问题激发了政治家和思想家们的极大兴趣，他们提出了各种各样的“理论”和“模式”。其中，较具代表性的有：“地球村”模式，世界政府模式，“和平区”与“动乱区”模式，“三大经济区”模式，“明冲突”模式，“单极霸权”或“单极主导下的多极合作”模式，两极或多极均势模式，等等。这些模式各以其独特的视角，试图勾勒出后冷战时代世界新秩序的“地图”。     

铁路通信信号标准及基础资料在线查询系统简介

利用现有成熟的信息技术,实现对标准文件的统一集中、规范化、安全化管理,为所属技术、科研人员提供简便有效的标准、规范的获取途径。     

动态信号采集分析仪(CY-1型)系统及原理

介绍了动态信号采集分析仪（CY-1型）的原理。该系统适用于多种物理模型试验，如船舶性能、船舶在风浪流自然载荷条件下对港口设施的影响（码头受到的撞击力与缆绳受到的拉力等）、桥墩防撞设施以及水工结构物等。实践表明，该系统精度高且操作方便，所以在物理模型试验中是不可或缺的。最后指出了可进一步完善该系统的若干方法。     

路基是有生命力的结构物——我国高速铁路路基建设取得的成就和需要继续解决的问题

系统归纳总结我国高速铁路路基技术体系形成、发展、完善的历程和高速铁路路基建设10年来在地基处理、路基结构层设计和填筑、路堤式路堑、过渡段、路基边坡支挡防护和防排水、路基结构与附属电缆沟槽和接触网支柱等基础的系统集成、沉降变形观测与评估等方面变革和发展取得的成就,指出正是高速铁路对路基工程刚度和变形的严苛要求,促进了我国高速铁路路基技术的革命性变革和不断进步,强化了路基结构物的建造理念,凝聚了路基结构物的生命力;同时,在非饱和土、膨胀土(岩)等方面阐释路基建设过程中仍需继续研究解决的问题。希冀本文有助于我国高速铁路路基技术体系的不断完善、创新发展,进一步提升我国高速铁路路基建造水平,增强满足列车安全、高速、舒适运营的生命力。     

Management of coastal eutrophication: Integration of field data, ecosystem-scale simulations and screening models

A hybrid approach for eutrophication assessment in estuarine and coastal ecosystems is presented. The ASSETS screening model (http://www.eutro.org) classifies eutrophication status into five classes: High (better), Good, Moderate, Poor and Bad (worse). This model was applied to a dataset from a shallow coastal barrier island system in southwest Europe (Ria Formosa), with a resulting score of Good. A detailed dynamic model was developed for this ecosystem, and the outputs were used to drive the screening model. Four scenarios were run on the research model: pristine, standard (simulates present loading), half and double the current nutrient loading. The Ria Formosa has a short water residence time and eutrophication symptoms are not apparent in the water column. However, benthic symptoms are expressed as excessive macroalgal growth and strong dissolved oxygen fluctuations in the tide pools. The standard simulation results showed an ASSETS grade identical to the field data application. The application of the screening model to the other scenario outputs showed the responsiveness of ASSETS to changes in pressure, state and response, scoring a grade of High under pristine conditions, Good for half the standard scenario and Moderate for double the present loadings. The use of this hybrid approach allows managers to test the outcome of measures against a set of well-defined metrics for the evaluation of state. It additionally provides a way of testing and improving the pressure component of ASSETS. Sensitivity analysis revealed that sub-sampling the output of the research model at a monthly scale, typical for the acquisition of field data, may significantly affect the outcome of the screening model, by overlooking extreme events such as occasional night-time anoxia in tide pools.